Wet-spinning system for fibers with multiple-hole spinnerets



July 21, 1970 w; HAR I 'MANN' WET-SPINNING SYSTEM FOR FIBERS WITHMULTIPLE-HOLE SPINNERETS Filed Nov. 16, 1967 2 Sheets-Sheet l I III[llll FIGQ2 FIG. 1

INVENTOR WALTER HARTMANN July 21, 1970- w. HARTMANN WET-SPINNING SYSTEMFOR FIBERS WITH MULTIPLE-HOLE SPINNERETS Filed Nov. 16, 1967 FIG. 3

2 Sheets-Sheet 2 'INVENTOR .WALTER HARTMANN 3,521,324 WET-SPINNINGSYSTEM FOR FIBERS WITH MULTIPLE-HOLE SPINNERETS Walter Hartmann, Wolfen,Germany, assignor to VEB Filinfabrik Wolfen, Wolfen, Germany Filed Nov.16, 1967, Ser. No. 683,654 Int. Cl. mud 3/00 US. Cl. 18-8 5 ClaimsABSTRACT OF THE DISCLOSURE A wet-spinning system for the spinning offibers with multiple-hole spinnerets, comprising a delivery pump for thespinning solution, a filtering device vertically arranged on said pump,a casing for housing said filtering device, a jacket at least partlyenclosing said cas a detachable rotatable and vertically slidable'tubefor receiving a precipitating bath for said spinning solution, for fiberformation therefrom upon emergence of the spinning solution from thespinneret.

In the art of providing spinning systems for the wetspinning process itwas felt to be advantageous to design a closed unit for every spinneret,because such an arrangement permits to utilize the spinning bath veryeffectively, to control the flow in such a manner that it will aid thefiber formation, and to remove the harmful gases formed during thespinning process in a more eflicient manner.

An arrangement is already known, in which a spinneret is placed in aspinning pot or bucket and a spinning tube is removably attached on thesame. An elastic hose connects thespinning tube to an overflow, saidhose effecting the detachable connection with the spinning bucket andaremoval of the spinning tube in such a manner that the spinneret ismade accessible and can be exchanged. The spinning solution passes froma filtering device to the spinneret through a tube.

This arrangement has the disadvantage that upon detachment of thespinning tube from the spinning bucket the elastic connection undergoesincreased Wear on the one hand by being subjected to bending andtwisting stress, on the other hand due to chemical attack so that itbecomes necessary to exchange this part quite frequently. Another factoris the difliculty of proper sealing between spinning tube and bucket,since for sealing the parts a certain turning is necessary upon lockingthem together and there is a limit due to the pliability of the elasticpart. 7

A further drawback of the known devices, particularly with the use oflarge spinnerets, is the fact that the spinning solution is passedthrough a restricting tube to the spinnerets after filtration. At thattime, air occulusions in the spinning solution may occur in the spinningchamber which occlusions are especially disadvantageous for the spinningprocess at the start.

It is the object of the present invention to provide a device whichpermits to avoid the above-mentioned shortcomings and which willfunction effectively and safely.

It is another object to provide a device which makes it possible toobtain fibers of fine titer even when using multiple hole spinnerets.

It is yet another object to provide a device which facilitates thespinning at the start of the operation and which makes exchange of partsin one unit possible Without interrupting the operation of other units.

Other objects and advantages will become apparent from the followingdetailed description and the drawings.

With the above objects in view, the invention is concerned with thecombination of a filtering means, a spinneret and a precipitating bathtube to an easily and effectively operating device.

United States Patent 0 p CC Such a device is provided according to theinvention by arranging a filtering device vertically upon a spinningpump on which it is secured. The filtering device has a casing which isprovided partly or completely with a double wall, to which a superposedtube conveying the precipitating bath liquid is detachably connected;the tube is slidably arranged for vertical displacement in the directionof flow. A spinneret is mounted on the exit opening of the casing.

The double wall of the filter casing forming a jacket is arranged tosurround the same completely when a rise in temperature of the spinningsolution occurs shortly before the spinning process starts. If noadditional heat ing of the spinning solution is necessary, the jacketwill preferably be provided only in the upper third of the filteringdevice.

The tube for the precipitating bath is detachably connected with thejacket and is rotatably and slidably mounted by means of an overflowdevice. Thus this device serves for holding and guiding the bath tube,during the exchange of spinning nozzles, since at that time theconnection with the jacket of the filtering device is interrupted. Thefilter, the bath tube and the overflow means are made of suitableplastic materials in order to make them lighter in weight and lessliable to chemical attack. Thus the filtering device may be made ofepoxy resin, the tube of the precipitating bath of polyvinyl chloride orepoxy resin, and the overflow means of polyvinyl chloride.

The device according to the invention has the advantage that no airocclusions can be present in the spinning chamber. The spinning becomessafer due to the immediate passage of the spinning solution from thefilter space through the holes of the spinneret into the precipitatingbath. Another advantage consists of the vertical slidability of the bathtube, whereby the nozzle becomes easily exchangeable, without thematerial of the bath tube being subjected to additional strain.Furthermore, the entire spinning device is easily exchangeable with fewtechnical manipulations and without interruption of different spinningunits of which the spinning system is built up during the spinningprocess becoming necessary.

The spinning device according to the invention will be more fullyexplained with reference to the accompanying drawings.

In the drawings,

FIG. 1 illustrates the overall arrangement of one embodiment of thespinning device, showing two of the spinning units side by side, theunit on the left-hand side in operation, and the unit on the right handside during exchange of the spinneret;

FIG. 2 is a longitudinal section through the lower portion of theleft-hand unit of FIG. 1 on a larger scale;

FIG. 3 is a longitudinal section through the upper portion of the unitshown in FIG. 1, left hand side likewise on a larger scale;

FIGS. 4 and 5 are horizontal sections on lines 4-4 and 55 of FIG. 3,respectively.

Referring first to FIGS. 1 and 2 of the drawing, I shows a base formounting the spinning units; arranged at the bottom is a pump 1a fordelivery of the spinning solution to a filtering'device generallydesignated by 10, and comprising the filtering means 2 and a casingtherefor designated by 3; between the surface of the filtering means 2and the casing 3, a space 19 is provided for passage of the spinningsolution delivered from the pump to the inside of filter 2 and fromthere to the spinneret designated by 5 and attached on the exit openingof casing 3 by a screw connection 6. For the upper portion of casing 3ajacket 4 is provided to which a tube 7 is detachably connected, thelatter serving for the admission of a precipitating bath liquid andhereinafter called the bath tube. Tube 7 is funnel-shaped in its bottomportion where the 3 precipitating bath is received; during operation,this portion is attached to the jacket 4 by way of screwing connectionwith the interposition of sealing means 7a. This funnel-shaped portionmerges into a tubular upper portion 7b which extends upward for aconsiderable length, as illustrated in FIG. 3.

The means for admission of the precipitating bath liquid to the spinningunit comprises a conduit 8 issuing from a source of bath liquid (notshown); the conduit leads to a tube 18 directly connected with it andthrough there to a space 4a between walls of the jacket 4 and throughopenings 4b into the bath tube 7. In tube 18, a valve 9 is provided forregulating the flow of the bath liquid.

The device further comprises a stretching trough 11 ararnged abovebath-tube '7 and capable of receiving the tubular upper portion 7b ofsaid tube when it is to be detached from the wall of jacket 4 forspinneret exchange. The trough 11 has a cover plate 13 with a centralopening through which the upper portion 7b of the bath tube isvertically slidable.

The last unit in the vertical arrangement is an overflow vessel 12 whichis generally shaped in the form of a container but having a fairly largeopening in the bottom through which a sleeve 30 is passed extendingdownwardly thorugh the central opening in plate 13 and upwardly into theinterior of vessel 12; this member is a mounting means for tube 7b whichis flanged at 38 and engages with the upper rim of sleeve 30 when inoperating (bottom) position. Vessel 12 is further provided with adischarge tube 31 serving for draining the excess amount of bath liquidand for returning it by means of a return conduit 28 (FIG. 1) to areservoir (not shown). This may be the source from which conduit 8 feedsbath liquid to bath tube 7 as described above.

Vessel 12 is provided with a lid 32 having a central hole 33 (FIG. 3).The vessel is mounted on plate 13 by means of brackets 34 and 35, whichare connectible by a screw connection 36 (FIG. 1) thereby providingconnection of vessel 12 to trough 11.

Toward the bottom end of the tubular portion 7b of bath tube 7,projections 16 are provided which are capable of engagement withsupporting brackets 17 on trough 11; this arrangement serves for holdingthe bath tube in raised position at the time of nozzle exchange.

In operation, the spinning solution is forced by means of pump 1athrough filter 2 into the space 19 and from there through the holes ofspinneret into the funnelshaped portion of bath tube 7, which acts as aspinning chamber. The precipitating bath liquid arrives over conduit 8and valve 9 into the space between the walls of the jacket 4 and fromthere through openings 4a and 41) into the spinning chamber, wherefibers 40 are formed; by a withdrawal means (not shown) the fibers 40are taken up and carried through the exit opening of tube 7b to furtherprocessing. The excess bath liquid escapes through tube 31 to the returnconduit 28 and from there to the reservoir mentioned before.

For the exchange of the spinneret unit 5, tube 7 is lifted until theprojection 16 engages with the brackets 4 17 on trough 11. At the sametime the flanged portion at the top of tube 7b slides beyond the top ofmember 30. The bath tube is held in lifted position by the engagement ofmembers 16 and 17 until the exchange of the spinneret has taken place.The other unit or units can in the meantime continue to operate withoutinterruption.

For returning'the bath tube into operating position, the members 16 and17 are disengaged and the tube of the precipitation bath will besecured. The bath tube is lowel'ed into the position shown at the lefthand side of FIG. 1 and ready for renewed operation.

What is claimed is:

1. Wet-spinning system for the spinning of fibers with a multiple-holespinneret, comprising a delivery pump for a spinning solution, afiltering device vertically arranged on said pump, a casing for housingsaid filtering device, said spinneret having substantially the samehorizontal cross-sectional area as that of said casing and beingdetachably mounted on the top edge of said casing, a jacketcircumferentially enclosing said casing for providing a coaxial spacetherearound, means for feeding a precipitating fluid into said coaxialspace, a vertical tube detachably mounted and hermetically sealed on topof said jacket for receiving said precipitating fluid from said coaxialspace, for fiber formation upon emergence of the spinning solution fromsaid spinneret; said tube being vertically movable from a first positionin contact with said jacket to a second position detached therefrom.

2. The spinning system as claimed in claim 1, further comprising invertical alignment with the tube a stretching trough and an overflowvessel thereabove, said tube slidably passing through the bottom of saidthrough into said overflow vessel, and disconnectable holding means forholding said tube in said second position during spinneret exchange.

3. The spinning system according to claim 1 wherein said means forfeeding the precipitating fluid comprise a conduit means communicatingwith said coaxial space and provided with a control valve.

4. The spinning device according to claim 2 wherein said overflow vesselis provided with a double-wall bottom portion, the outer wall of saidbottom portion being pro vided with a discharge conduit.

5. The spinning device according to claim 2 wherein said holding meanscomprise a first holding part mounted on said tube and a second holdingpart mounted on said trough, said tube further being rotatably movablefor mutually engaging said first and second holding parts in said seconddetached position of the tube.

References Cited UNITED STATES PATENTS 5/1961 Edwards et a1 188 8/1962Soehngen 188

